1. Field of the Invention
This invention relates to providing light for forming images and, more particularly, to providing light for forming images by a passive viewer.
2. Description of the Prior Art
Still photography, motion pictures and television were influenced by the way artists represented physical reality in paintings, as if through a window. A highly detailed perspective image is provided, typically within a rectangular frame. All provide highly detailed images which induce the viewer to cooperate with the cameraman's "vision" by assuming the artificial perspective of the representation. The viewer is enabled to deliberately suspend disbelief that the images themselves are not a real object space. The degree to which the viewer is thus enabled is influenced not only by the image resolution but by the field of view. It is usually thought desirable to increase both. For example, very high resolution commercial television standards have been formulated for increasing image quality. Such approaches typically increase the number of horizontal lines scanned to a number significantly greater than present standards. Larger format movie film such as 70 mm has been used to increase detail. Also, panoramic movies, e.g., "Cinerama" increased the field of view to increase realism. Various stereoscopic television approaches have also been conceived or developed to increase realism.
All of these traditional media take a rather objective view of the physical world. The image is framed by a window through which the viewer can gaze in any direction "into" a representation of an object space. Events are presented in both movies and television in a series of different action scenes in a story line which the viewer can observe from a stable and seemingly quasi-omniscient point of view. The viewer is led to take what appears to be a view of the world as it really is. Yet the choice of image and its perspective is picked by the creator of the image and the viewer actually assumes a passive role.
A sensorama simulator was disclosed by Heilig in U.S. Pat. No. 3,050,870. The senses of an individual were stimulated to simulate an actual experience realistically with images, a breeze, odors, binaural sound and even motion. Heilig also disclosed a stereoscopic television in U.S. Pat. No. 2,955,156. This also was passive.
"Virtual reality," in an electronic image context, goes even further in the direction of increased realism but enables the viewer to take a more active role in selecting the image and the perspective. It means allowing a viewer's natural gestures, i.e., head and body movements, by means of a computer, to control the imaged surroundings, as if the viewer were seeing and moving about in a real environment of seeing, hearing and touching. Due to the myriad of possible actions of the viewer, a corresponding multiplicity of virtual activities needs to be available for viewer choice. This would represent the ultimate in artificial experience.
A user of a "virtual reality" device will typically don a head-mounted display which provides images of a virtual space that are matched to the sensed position and orientation of the head of the user as the user moves his head in space and time (e.g., the x, y, z position of the head and/or the roll, pitch, yaw attitude of the head). For example, a Fakespace BOOM3C is a Binocular Omni-Orientation Monitor that provides visual displays and tracking integrated with a counterbalanced articulated arm for full six-degree of freedom motion (x, y, z, roll, pitch, yaw) and provided by Fakespace, Inc., 241 Polaris Ave., Mountain View Calif. 94043. Another example would be a wireless magnetic motion capture system such as the STAR*TRAK of Polhemus Incorporated of 1 Hercules Drive P.O. Box 560 Colchester Vt. 05446. It provides six-degree-of-freedom (position and orientation) data from up to 32 sensors capturing data at up to 120 Hz.
The images for such devices are created by a computer program with the assistance of pre-stored image information that is retrieved according to the user's head movements and presented to the user's eyes. The user's head may be coupled to the display. The aim is to present panoramic images covering a wide field of view in order to immerse the user in an artificial reality with which he can interact, as if real. The degree of artificiality need not be total and can instead constitute an "augmented reality" with some artificial objects or symbols superimposed or interposed within the real world as viewed with a see-through, head-mounted or head-display.
These advances take advantage of converging technological developments in projection optics for head mounted and head-coupled displays (including virtual retinal displays), the ever-increasing computational power of image processing computers, specialized sensors such as gloves designed to sense hand and finger movements, exoskeletons, and the like. They can be expected to lead to exciting interactive games and other new forms of interactive experiences within virtual worlds.
This new paradigm represents a very great improvement over the present imaging technology. It joins immersion to interactivity to increase the level of experience. It is now being applied to gaming applications and others such as virtual museums, architectural and interior design mockups, facility tours, "aircraft" rides and the like.
The new paradigm would likewise seem to hold the potential for an improvement over the old ways of traditional entertainment such as drama, comedy, documentaries, and the like. By joining immersion and interactivity, the user would be enabled to enter a completely new realm of artificial experience. The user would be given a very high degree of freedom, under his own volition, to navigate in the virtual world and to participate in completely new forms of such entertainment, where the user's own actions influence the sequence of images and audio provided.
Traditional entertainment applications, on the other hand, such as drama, comedy, documentaries, and the like, have not yet been explored by these new technologies. This could be because the traditional applications have usually been presented for passive enjoyment by the viewer. Even though immersion would provide a better experience, interactivity would be contrary to these known traditional entertainment applications, such as storytelling, where people like to relax and be passively led through stories and participate vicariously. Another obstacle would seem to be that the level of complexity of the possible alternative scenarios, depending on the user's actions, would need to be higher in the traditional arts than for the more predictable and mechanistic art of gaming.
For all these various kinds of virtual reality applications, the creation of many possible scenarios for viewer selection creates a massive demand for electronic image storage space and there is also the problem of a disconcerting time lag between the viewer's action and the response of the imaging system. These problems make this emerging technology hard to achieve using presently available hardware. The software task is equally daunting.